This invention relates generally to entertainment and architectural lighting, and more specifically is a device to control the hue, saturation, and brightness of color emanating from a lighting module. The device also allows a user to control beam size and the distribution of light.
Colored light sources are often used in the theater, television, touring productions, and architectural applications. The color is varied in hue, saturation, beam size, and/or distribution to obtain a particular artistic effect. The artistic requirements might be that the color, size and or distribution remain static, or that those attributes change over time. Cost, speed of changing, the quantity of colors produced, the smoothness of color changing, compact size and weight, and the efficiency of transmitting light through color filters are all factors in the practical usage of a color changing system. A smooth distribution is desired for the light and color when the light beam is projected onto a surface that is perpendicular and off axis. Off axis projection is common when the walls of a building are being illuminated.
One prior art method of changing the color of a light source is to manually insert a specific color filter in the light""s path to obtain a specific artistic result. This method required that the filter be changed if it did not result in the exact color that was desired. Changing a color filter required the procurement of the new color filter and the replacement of the old filter. This use of specific filters makes it impractical to change the color of the light during a performance. The filters most often used in these applications are dyed or coated plastic films called gel. The durability of this material is limited and requires frequent replacement when used with a high powered light source. The general efficiency of light transmission is low. In the creation of certain dark blue and red colors, transmission can be as low as 2%.
Since the introduction of the use of gel as a color filter, inventors have created several methods to remotely change the color of a light source utilizing gel. The Scroller(trademark), by Wybron of Colorado Springs, Colo., assembles a plurality of different colored gels into a band that is fitted around a pair of scrolls. The scrolls are spaced on opposite sides of the light source""s aperture. By rolling the scrolls, any of the colors on them can be accessed. This method and its variations, embodied in products manufactured by a number of companies, is a compact solution to changing color. However, the method has many deficiencies. The mechanism to locate and control the scrolls is costly and complex. Gel deteriorates in a short time when rolled back and forth on a scroll while being subjected to heat from a light source. Furthermore, the number of different colors that can be used at one time is limited to the number of colors that can be assembled into a single gel band. The slow speed of color changing, the low transmission efficiency of the filter material, and the need to frequently replace gel filter material are also deficiencies in this prior art method. This invention includes no method to change beam size or distribution.
U.S. Pat. No. 5,126,886, to the present inventor Richardson, discloses an improved scroll type gel color changer. Yellow, cyan, and magenta scrolls of varying color saturation are located in series in the optic path. The various position locations of the three scrolls result in an unlimited number of colors. Colors can be changed quickly or slowly. The transition from one color to another is smooth. The mechanism of this color changing system has three times the complexity of the single scroll system and therefore suffers in cost and reliability. This invention includes no method to change beam size in or distribution.
Other inventors have created several other methods to change the color of a light source utilizing interference or dichroic type filters. Dichroic filters are efficient in transmitting light and are durable, but they are costly. U.S. Pat. No. 5,073,847, to Bornhorst, issued Dec. 17, 1991, and U.S. Pat. No. 5,186,536, to Bornhorst, et al., issued Feb. 16, 1993, disclose a method of tilting a series of dichroic color filters to create various colors. However, this system is limited in the quantity of colors that it creates, the excessive cost of the color filters, and the fact that the system requires a very complex control mechanism.
U.S. Pat. No. 4,914,556, to the present inventor Richardson, issued Jun. 30, 1992, discloses an assembly of yellow, cyan, and magenta filter wheels, each with varying levels of color saturation. The positioning of the wheels between a light source and an aperture determines saturation and hue of color at the aperture. This module creates an unlimited quantity of colors, however at a relatively high cost. The filters of this module must be many times greater in size than the aperture. This results in a very high cost to aperture size ratio.
In the past, the divergence and distribution of a light source was changed by manually replacing the light source type to obtain a specific artistic result. Utilizing a different reflector configuration could also change it. The use of a specific lamp for each type of divergence sought makes it impractical to change the divergence of the light source during a performance. Therefore, more overall lighting fixtures are required to accomplish the desired artistic results.
U.S. Pat. No. 4,973,306, issued Nov. 20, 1990, to Bornhorst, discloses a series of diffusion panels that are introduced from the sides of a beam of light. This creates various beam divergences. However, this fails to create a range of beams with a smooth field of illumination. Further, this system comprises a complex mechanism that is costly and unreliable. It also provides no method to change beam distribution.
U.S. Pat. No. 5,073,847, also to Bornhorst, discloses another diffusion mechanism. A series of rotatable diffusion panels are arranged in a radial array. Rotation of the panels into the light path diffuses the light beam. This mechanism also proves to be expensive and provides no method to change the beam distribution. There is also an insufficient range of beam sizes to provide a smooth transition from narrow to full diffusion. To control the beam size the lens requires that it be changed.
U.S. Pat. No. 5,665,305, issued Sep. 9, 1997, to Belliveau, et al., discloses a method of intervening one or two lenticular panels to change beam divergence and or beam shape. These panels are oriented so as to be orthogonal to one another when engaged. This method does not allow for continuous changes in beam size or shape.
Accordingly, it is an object of the present invention to provide a device that, given a white light source, can emit any color chosen by a user. The device can also change from one color to any other color quickly and smoothly.
It is another object of the present invention to provide a light beam divergence and distribution module that is compact, and that is inexpensive to produce and to maintain. The module is of simple construction, and is therefore very reliable.
It is a still further object of the present invention to provide a device that efficiently transmits light.
The present invention is a lighting module that projects various colors, hues and intensities of light. Further, the module can change the divergence and distribution of light. The device includes a light source and a reflector to direct the light along an optic path in a generally parallel direction. The invention does not provide a beam that is parallel or even somewhat parallel. It is intended for applications in which a somewhat diffused beam is required, or in which the beam is to be diffused in at least one direction.
In addition to the light source, the module comprises a filter assembly with at least one filter therein, and a size diffusion filter. The filter assembly controls the size and color of the light beam. A system diffusion filter spreads the light in one or more desired directions so that fewer modules are required to light a given area.
An advantage of the present invention is that it provides a single, compact unit that allows the user to project any color, hue, size distribution, or intensity of light desired. This eliminates the need for multiple pieces of equipment.
Another advantage of the present invention is that it is simple and inexpensive to manufacture and is therefore reliable and easy to maintain.
These and other objectives and advantages of the present invention will become apparent to those skilled in the art, in view of the description of the best presently known mode of carrying out the invention as described herein and as illustrated in the drawings.